<b>No one should feel pinges of guilt at your wedding when they decide to throw out your useless wedding favor.</b> So make it something indispensable, as opposed to just putting more crap out there into the world.
Brownie in a Cup ~ Wipe the outside of the cup with rubbing alcohol. Use an oil based Sharpie paint marker, then write the instructions onto the cup. Let the Sharpie dry completely for 24 hours. Place your cup in a cold oven, then bake at 450 degrees for 30 minutes. Crack your oven door and let the cup cool down with the oven to prevent cracking. This would be great as a gift, add the dry ingredients and wrap.